function [nu,M] = Rx(U)
% R - 用守恒变量U计算A的右特征值\nu和特征向量矩阵
%   
    [rho,u,v,p]= U2Variables(U);
    E = U(4);
    H = (E+p)/rho;
    a = sqrt(1.4*p/rho);
    nu=[u-a;
        u;
        u;
        u+a;
       ];

    M = [1,0,1,1;
         u-a,0,u,u+a;
         v,1,v,v;
         H-a*u,v,(u^2+v^2)/2,H+a*u];
end
